Dan buoy indicators



Oct. "'25, 1960 s. K. ZASADA 2,957,446

DAN BUOY INDICATORS Filed Dec. 22, 1958 4 Sheets-Sheet 1 FIG. 2.

INVENTOR STEVEN K. ZASADA BY Maw ATTORNEY Oct. 25, 1960 s. K. ZASADA 2,957,446

DAN BUOY INDICATORS Filed Dec. 22, 1958 4 Sheets-Sheet 2 INVENTOR STEVEN K. ZASADA BY MW ATTORNEY 4 Sheets-Sheet 3 Filed Dec. 22, 1958 FIG. 4.

INVENTOR STEVEN K. ZASADA ATTORNEY Oct. 25, 1960 s. K. ZASADA DAN BUOY INDICATORS Filed Dec. 22, 1958 4 Sheets-Sheet 4 0X 68 O O O 0 0 O O O O Q o O O O O o 0 o 64 o o o 0 0 o O o 0 o o 0 0 0 0 0 0 O o o o o o o o o o o o 0 o o o o o o o o 0 o 0 0 o o O o o 0 o O 0 0 FIG.5.

FIG. 6.

. i II INVENTOR STEVEN K. ZASADA ATTORNEY Unite DAN BUOY INDICATORS Steven K. Zasada, Arlington, Va., assignor to the United States of America as represented by the Secretary of the Navy The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to Dan buoy indicators for a minewarfare buoyage system to warn approaching ships of the direction and location of a mine field.

In the usual type of mine sweeping operations a number of channels are swept clear by minesweepers and Dan buoys are set out to mark the channels and the location of the mine fields. Usually these channels are swept clear of mines from time to time to remove mines which may have been subsequently set out by enemy planes or submarines. Further minesweeping operations may be conducted in order to clear a larger channel or a large area. In this case the usual practice is to retrieve the Dan buoys and place them at the new edge of the mine fields and: to install new channel markers. The Dan s Patent buoys are usually repainted and, of course, must be re- 7 trieved which requires a large amount of time, money, and effort.

In the past numerals or other indicia were painted on the buoys to warn approaching ships Due to the low freeboard or the small area of the buoy above the water and waves, the indicia were difiicult to identify from-.a distance while even a moderate sea tended to completely obscure the indicia.

The primary object of this invention is to disclose a high visibility indicator which may be fastened to a Dan buoy.

The high visibility indicator comprises a triangular frame which holds a plurality of removable, octagonal markers to indicate the direction and location of the mine field to passing ships.

Another object of this invention is to avoid retrieving and repainting indicia on the buoy which is accomplished by making the markers removable so that they may be easily changed without removal and repainting of the whole buoy.

Another object of this invention is to disclose an octagonal marker which is painted with two contrasting colors whereby the angular position of the marker will indicate the compass direction of the mine field.

Other objetcs of this invention are to disclose a perforated aluminum indicator which provides an excellent radar reflector with no tendency to heel over in a strong wind and dip below the effective wave height.

Other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the annexed drawings, which illustrate a preferred embodiment, and wherein:

Fig. 1 is a pictorial view of a Dan buoy showing the obscuring effect of the waves on the old type of markmgs;

Fig. 2 is a pictorial view of the new indicator mounted on a Dan buoy;

Fig. 3 is a side elevation view of the Dan buoy indicator frame mounted on a buoy;

of the mine fields.

Fig. 4 is a top view of the indicator frame;

Fig. 5 is a view in elevation of the position indicator showing the contrasting color markings for compass indication of the mine fields;

Fig. 6 is a cross-sectional view taken along the lines 6-6 of Fig. 5', and

Fig. 7 is a view in elevation of the numerical indicator.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in Fig. 1 a buoy assembly 10 comprising a buoyancy chamber 12, a counterweight, mooring \m're reel 14, an anchor block 16 joined to reel 14 by wire 18, and a fiagstatf 20. This Dan buoy may be one similar to that disclosed in copending patent application, Serial No. 747,319, filed July 8, 1958, Navy Case No. 22,455, for Buoy by Mark Kurtz, assigned to the same assignee as the present invention. This buoy assembly 10 will weigh about 400 lbs.

As shown in Fig. l numerals 22 (number 5) are partially obscured by the waves 24, while, from a distance, the cumulative elfect of a number of waves will limit visibility to the effective height of the waves which is the average maximum height of the waves. The buoyancy chamber 12 is only 3% feet high with the waterline 26 being fourteen inches below the top of the chamber 12 while the numerals 22 are only 8 inches high.

Referring to Fig. 2 (which illustrates a preferred embodiment) a buoy assembly 10, comprising chamber 12, reel 14, anchor block 16, wire 18, and fiagstaff 20, is shown having indicator assembly 28 fastened to the top of chamber 12 and clamped to flagstafi 20. A triangular indicator frame 30 is fastened to the top of the buoyancy chamber 12 to support three removable indicators 32, which are octagonal in shape and are 19 inches wide. These indicators 32 provide a large, high visibility surface above the buoyancy chamber 12 which may be seen from any direction without being obscured by waves 24.

Three indicators 32 are placed on the indicator frame 30 to provide 360 degree visibility of the buoy so that the markings may be read from any direction of approach of a ship and despite rotation of the buoy about its vertical axis.

Referring also to Fig. 5, the indicators 32 are painted in two contrasting colors and are octagonal in shape so that the dark color may be set to one of 8 compass points to indicate the direction of the mine field. The compass directions are set to those conventionally used by northern hemisphere observers, thus N at the top, S at the bottom, E at the right, and W at the left of the frame. The NW, NE, SE, and SW directions are placed at the corners of the frame. The buoy is then set out at the safe edge of the mine field.

Referring to Fig. 3, a side elevation view of the frame 30 is shown where a base ring 34 has three lugs '36 which are bolted to three studs 38. The studs 38 are welded to the top of the buoyancy chamber 12. Three square indicator holder frames 40 are welded to the base ring '34 and to each other. Each holder frame 40 comprises two vertical side frame members 42 consisting of angles where the inside parts of the angles face toward each other and toward the outside and two horizontal top and bottom frame members 44 and 45 consisting of angles where the inside parts of the angles face each other and toward the fiagstaff 20. A brace 46 extends diagonally across each holder frame 40.

Two keepers 47 made of angle are welded to the two side frame members 42 and one keeper 48 welded to the bottom frame member 45 to hold the indicator 32 in the proper position. A latch 49, comprising two fingers 50 pivotally mounted by rivets 52 to top frame member 44, holds indicator 32 inplace despite the movement of the buoy and allows the indicators to be easily replaced without retrieving and repainting the whole buoy.

Referring also to Fig. 4, which shows a top view of the frame 30, trapezoidal-shaped tie pieces 54 are welded at the corners of the frame 30 to provide sufficient stiffness. Three J-shaped equalizing strips 56 are welded by their longer ends to the tie pieces 54 at the top of the frame 30 and extend toward the flagstaif 20 where they are clamped by a clamp 57 comprising half-rings 58, bolts 60, and nuts 62. Fig. 4 shows an upper circular section of the flagstaff 20, but does not show the rest of the buoy assembly 10.

In order to indicate the direction of the mine fields, the compass directions are painted as shown in Fig. 3 with N on top frame member '44, S on the bottom keeper 48, E and W on the side keepers 47 and NE, NW, SW and SE on the corners of each individual holder frame 40.

The direction of the mine field is actually indicated to the observers on a passing ship by the octagonal position indicator 32 shown in Figs. 5 and 6. Eight angles 64 are welded together as shown to provide an octagonal frame for a perforated sheet 66 welded to angles 64. A stiffener 68 extends across the back of the sheet 66 for further support.

The sheet 66 is painted a dark blue on the upper half 9 and painted white on the lower half 70 to indicate the direction of the mine field while the location of the buoy usually determines the safe edge of the mine field. An arrow 71 and the legend Dangerous Waters are painted in black above the top of the upper half 69 of sheet 66 on an angle 64 so that the personnel on the mine sweepers may easily set the arrow to the proper compass direction on the holder frame 40 to indicate the direction of the mine field.

The sheet 66 is perforated with a plurality of inch diameter holes spaced inch apart on a series of parallel lines. The holes materially reduce the wind resistance of the indicator assembly 28 to minimize any heeling effect of the buoy in strong winds.

Referring to Fig. 7, a numerical indicator '72 is shown which has the same construction as indicator 32 in Figs. 5 and 6, but is painted white with a red edge and with 12 inch numerals 74 painted black. The numerical indicators 72 are used for marking the center line of a mine-free channel or may be used for navigation markers if the whole area is mine-free.

The indicators 32 and frame 30 are made of commercial grade aluminum alloy for minimum weight except for studs 38 and their associated nuts which are made of stainless steel.

The indicators 32 are 19% inches in diameter across the octagonal flats and, being made of conductive aluminum, provide an excellent reflector for search and navigation radar.

The removable indicators 32 by reason of their appreciable increase in size over the prior markings and their higher position above the buoyancy chamber 12 provide a high visibility indicator for safe and reliable navigation of ships near mine fields or dangerous waters.

It should be understood, of course, that the foregoing disclosure relates to only preferred embodiments of the invention and that it is intended to cover all changes and modifications of the examples of the invention herein chosen for the purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

What is claimed is:

A Dan buoy indicator for a mine warfare buoyage system comprising a base ring adapted to be fastened to a Dan buoy, three square frame members wherein each is attached by a first side to said ring and attached by the two sides adjacent said first side to the other square frame members whereby a triangular shaped body extending away from said buoy is formed, three J-shaped equalizing strips attached by their longer ends to the end of said triangular shaped body away from said buoy and having their shorter ends extending toward the central part of said body, a circular clamp mounted around said shorter ends of said J-shaped clamps for fastening said clamps to said buoy, a plurality of keepers wherein one keeper is placed at said first and two adjacent sides of each square frame members, a plurality of latch fingers wherein one pair of fingers is mounted at the fourth side of said square frame member, and three octagonal indicators wherein one indicator is removably fastened by each frame member for indicating the location of a mine field.

OTHER REFERENCES Publication: Popular Science, September 1953, page 15. 

